Many auditoriums and gymnasiums in schools, and social halls in churches, cannot allot space for permanent staging or bleachers to accommodate singing groups where multi-level staging is required, or to accommodate spectators when special events such as concerts or sporting events are scheduled. To meet this demand for staging, various suppliers have merchandised collapsible or demountable support frames for staging platforms or seating. Examples of collapsible bleacher systems are found in U.S. Pat. No. 3,995,832 (Dec. 7, 1976) and U.S. Pat. No. 4,363,197 (Dec. 14, 1982). Staging support apparatus is illustrated in U.S. Pat. No. 4,638,604 (Jan. 27, 1987) assigned to the assignor of the present application.
It is an object of the present invention to provide a collapsible support frame structure which can occupy very little space in the collapsed state but which can be easily advanced for supporting staging or seating panels.
It is a further object to provide a support frame which can be handled by unskilled persons with no need for special tools in assembly or disassembly. Another object is the provision of a support structure which can be used in horizontal multiples by bridging between structures, thus reducing the need for, and cost of, individual supports for all adjacent horizontal tiers. The components which require manual lifting preferably shall weigh not more than 130 pounds and shall be adaptable to use of guard railings, chair rails, skirting enclosures and so forth. Suitable leveling devices can be readily adapted to the system.
Briefly, the invention comprises a series of multilevel frames forming an understructure, each with common vertical supports, and side gates for each level, between said frames, which pivot on the vertical supports and fold toward each other in the collapsed state. Horizontal lateral spacers stabilize the side gates. A series of support panels are each engaged at two opposed corners with vertical supports and at the remaining corners with brackets on the gates adjacent vertical supports so that each level is securely stabilized against shifting. The support panels are reinforced flat structures which can be used with either side up and optional surfaces as desired.